BONE, PATHOLOGICAL CONDITIONS OF. 



451 



secreted, and partly because it seldom takes 

 the shortest route to the surface, but proceeds 

 by devious and intricate windings. At length 

 the tumour, at one limited and almost circum- 

 scribed spot, becomes soft, then assumes a dark 

 red or purple colour, finally a small slough 

 forms on the surface and it bursts, giving exit 

 in general to a greater quantity of matter than 

 the size of the abscess would have led us to 

 anticipate. The abscess does not collapse, and 

 although the discharge may continue in pro- 

 fusion for months, the size of the tumefaction 

 is never proportionally diminished. After it 

 has burst, a small papilla of very red granu- 

 lation (a most unfailing symptom of the exis- 

 tence of a diseased bone underneath) is pushed 

 out through the aperture. From the centre of 

 this a small drop of matter can generally be 

 pressed, and through it the discharge flows ; 

 never for obvious reasons profusely at a time, 

 but still so constantly as to soil the dressings 

 and the bed-clothes extensively in a single 

 night. When a probe is passed down to the 

 bottom of this ulcer, which it is not easy al- 

 ways to accomplish, the bone is felt completely 

 denuded, soft and rotten, and the instrument 

 sinks into it with very little resistance. Most 

 frequently the earthy material of the bone is 

 removed by the absorbents ; sometimes a small 

 portion of it thus detached is washed off by 

 the discharge, and is occasionally found block- 

 ing up the little orifice, occasioning a good 

 deal of irritation and pain, and almost always 

 an access of fever. Sometimes the remains of 

 the bone come away in a larger mass, quite 

 dead, light, and porous, and, when dried, per- 

 fectly friable. 



Previous to the formation of the matter, 

 however, the pathological state of the bone has 

 undergone a remarkable change. Hitherto we 

 have seen that an increase of vascularity oc- 

 curred at an early period, and preceded the 

 deposition of the soft and cheesy substance; 

 but in proportion as this deposit is increased in 

 quantity, the vascularity decreases, and with it 

 the vitality of the bone. " If a scrofulous 

 bone be injected at an early period," says Mr. 

 Lloyd, " or before the whole of its cancellous 

 structure is altered, the injection very freely 

 enters its vessels ; but if it be injected at a 

 more advanced period, there evidently appear 

 to be fewer vessels, though it is very probable 

 that a fine injection may be forced into vessels 

 which had previously ceased to carry blood." 

 In the correctness of this observation Sir B. 

 Brodie coincides, as well as in the opinion 

 " that this diminution of the number of ves- 

 sels, and, consequently, of the supply of blood, 

 is probably the proximate cause of those exfo- 

 liations which sometimes occur, where the 

 disease has existed for a considerable length of 

 time, especially in the smaller bones."* 



Although carious ulceration, or, as it would 

 be more correctly termed, absorption of bone, 

 is so frequently attended by the formation of 

 matter and abscess, yet such is by no means a 



* See Lloyd on Scrofula, p. 123, and Brodie on 

 the Joints, last edition, p. 195. 



necessary consequence at least, we have ex- 

 amples of the removal of large portions of 

 bones without any such unfortunate accompa- 

 niment. These principally appear under two 

 distinct forms : one, where such absorption is 

 the result of inflammatory action within the 

 bone itself, the most familiar illustration of 

 which is to be found in the caries of the spine 

 attending on some cases of angular curvature : 

 the other, where the absorption has been occa- 

 sioned by the pressure of an aneurism, an 

 abscess, or other tumour in the immediate 

 neighbourhood. 



Mr. Pott, and others who have described 

 this caries of the spine, mention that, at first, 

 the bodies of the vertebrae seem to spread so 

 as absolutely to become larger than in a state 

 of health; that the ligaments are loose and 

 detached, and the intervertebral cartilages sepa- 

 rated from the bone. The first part of this 

 description is certainly not correct, for in all 

 the subjects we have had opportunities of ex- 

 amining, nothing like an enlargementor swelling 

 of the bone appeared. It must be recollected 

 that dissections of this disease at an early 

 period are rarely met with never unless the 

 patient had been accidentally seized by some 

 mortal affection soon after the spine had been 

 attacked. It may, therefore, be supposed that 

 these early descriptions were taken from ana- 

 logy with what other bones suffer in scrofulous 

 disease, and it is well known that, until a com- 

 paratively recent period, it was a universally 

 received opinion that the heads of bones be- 

 came actually enlarged under similar circum^ 

 stances. 



Sir B. Brodie, who has given the clearest as 

 well as the most succinct description of caries 

 of the spine we have met with, considers that 

 its pathological history may be arranged under 

 three heads. 



1 . " It has its origin in that peculiar sof- 

 tened and otherwise altered condition of the 

 bodies of the vertebra, which seems to be 

 connected with what is called a scrofulous state 

 of constitution. In these cases ulceration may 

 begin on any part of the surface, or even in 

 the centre of the bone, but in general the first 

 effects of it are perceptible where the interver- 

 tebral cartilage is connected with it and in the 

 intervertebral cartilage itself."* 



As this is an instance of scrofulous caries, 

 such as has been already noticed, it should 

 perhaps have come more legitimately under 

 consideration in that part of our article. We 

 prefer, however, to take a distinct and separate 

 view of caries of the spine, because the locality 

 invests the disease with some peculiarities. 

 For instance, this scrofulous caries is almost 

 invariably attended by abscess, and we find 

 these collections to be much larger in quantity 

 of contents, and, if possible, more sluggish in 

 approach to the surface than when situated 

 elsewhere. Their existence, therefore, may not 

 only not be suspected, but the symptoms occa- 

 sioned by them during life may be attributed 

 to a totally different cause. They are least 



* Brodie on the Joints, p. 243. 



2 G 2 



